BERLIN — A woman is facing criminal charges of double-dipping on methadone.

State police said Friday they cited Sara Tucker on charges of false pretense and 21 counts of prescription fraud. They said an investigation began after police learned she allegedly sent a fraudulent letter to her primary care physician at Central Vermont Medical Center in Berlin.

According to police, the letter was purportedly from BAART Behavioral Health Services and indicated Tucker, 34, was no longer being treated with methadone at its Granger Road clinic. The letter requested that Tucker’s treatment be taken over by her primary care physician.

Police said that for a time, Tucker was receiving methadone from her doctor while still being treated with it at the BAART clinic.

Police further allege Tucker was also receiving controlled substances from her counselor at Family Psychiatry Associates in Berlin. According to police, the 21 counts of prescription fraud are based on the number of visits during which Tucker failed to disclose she was being prescribed methadone at BAART.

Police did not specify Tucker’s hometown but said she is to be arraigned in Washington County criminal court in Barre on Feb. 20.